1. Field
The present disclosure relates to an apparatus for attaching substrates to one another, and more particularly to an apparatus for attaching substrates together in which a height adjustment of a chamber is facilitated.
2. Background
With the development of an information society, requirements for display devices have increased. In response, various flat panel display devices, such as a liquid crystal display, (LCD), plasma display panel, (PDP), etc. have been developed.
LCD display devices are now widely used in various devices such as televisions, mobile phones and computer displays due to their advantages of superior video quality, light weight, slim profile and low power consumption. A LCD display device typically includes a liquid crystal material injected between a thin film transistor (TFT) substrate formed with electrodes and a color filter (CF) substrate coated with a fluorescent substance. During the manufacture of an LCD display device, an apparatus used for injecting liquid crystals and aligning and attaching two substrates is referred as a substrate attaching apparatus.
In the substrate attaching apparatus, substrates are mounted on upper and lower stages placed in an upper chamber and a lower chamber, respectively. The upper chamber and the lower chamber are then brought together to form a sealed attaching space. Air is exhausted from the sealed attaching space to form a vacuum state, and the two substrates are aligned accurately and then attached to each other.
However, because, an inside of the chamber is in a vacuum state and the outside of the chamber is under atmospheric pressure, the chamber may be physically deformed. Such deformation of the chamber may cause a deformation of a driving part used to move the upper and lower stages together. This can obstruct the up and down movements of the upper and/or lower stages of the chamber. Due to these deformations, undesirable stress is generated in the chamber, and a malfunction of the attaching apparatus may occur, thereby shortening a lifetime of the attaching apparatus.
FIG. 6 shows a location of a chamber transportation part in accordance with a conventional substrate attaching apparatus. When an inside of the chamber of the substrate attaching apparatus is evacuated so that it assumes a vacuum state, the atmospheric pressure is applied to an outside of the chamber. By such pressure, the chamber may be deformed, as illustrated by dotted line in FIG. 6. Note, this deformation has been magnified to better illustrate the deformation.
As shown in FIG. 6, the stress generated by the pressure differentials may causes deformation of the lower chamber 100 and the upper chamber (not shown), and deflection of the vertically standing chamber transportation parts 130. Due to this deflection, a relatively large force is required to lift or lower the lower chamber 100. Also, the chamber transportation parts 130 are not exactly vertical, but rather are inclined slightly. As a result, there is a difficulty in a height adjustment.
As shown in FIG. 6, the stress generated by the pressure differentials may causes deformation of the lower chamber 100 and the upper chamber 110, and deflection of the vertically standing chamber transportation parts 130. Due to this deflection, a relatively large force is required to lift or lower the lower chamber 100. Also, the chamber transportation parts 130 are not exactly vertical, but rather are inclined slightly. As a result, there is a difficulty in a height adjustment.
Further, due to the deflection of the chamber transportation parts 130, it is difficult for the chamber transportation part 130 to control easily the up/down movement of the lower chamber and the chamber transportation part 130 is subject to increased stress when moving the lower chamber upward and downward. Therefore, the lifetime of the chamber transportation parts 130 may be shortened.